Superman turns 77 on Tuesday, June 30. The date marks DC Entertainment's official date-of-birth for the Man of Steel, who debuted on the pages of a comic book this month in 1938.

Superman debuted in Action Comics No. 1 in an issue published in June 1938, which showed off the stunning feats of the hero and the life of his unassuming alter-ego Clark Kent. With Superman's birthday upon us, here are seven key facts about the superhero who skyrocketed to international fame.

The comic was created by a couple of buddies: Two childhood friends Jerry Siegel and Joe Shuster created the first comic after prior iterations of Superman were rejected. Their first idea for Superman was a telepathic, mad-scientist villain. Later he became the hero now known worldwide. The first issue featured relatively small feats of justice, including rescuing an innocent woman off of death row and helping another woman with her abusive husband.

The buddies sold low: The rights to Superman were signed off to National Allied Publications, the predecessor to DC Comics, for just $130 and $10 per page created, according to BT.  Later, the authors and their heirs reportedly struck deals that allowed them to receive more payment.

A copy of the first comic will cost you millions of dollars. It's the Mona Lisa of comics: A copy of Action Comics No. 1 sold for $3.2 million in an Ebay auction in 2014. Forty-eight people were in the running for the rare comicbook and the bidding began at $1 million. Nicolas Cage previously paid $2.16 million for a copy of the comic book.

Collectibles dealer Darren Adams, who auctioned of the issue in 2014, told Variety, it's “the Mona Lisa of comics and stands alone as the most valuable comic book ever printed."


Superman first appeared on screen 67 years ago: Actor Kirk Alyn played the Man of Steel in a 1948 serial show in movie theaters, according to the Los Angeles Times

Superman has since been everywhere: Merchandise featuring the superhero can be found online, the Man of Steel's likeness (or famous "S" logo) on just about everything imaginable, including T-shirtssteering wheel coversduct tape and giant wall decals. The hero has also been featured in numerous movies, cartoons, television series, comic books, musicals, etc. The movie "Superman v. Batman: Dawn of Justice" is slated to be released next year and has drawn a significant amount of attention.

Superman debuted just before Batman: The first Superman series comic book debuted in the summer of 1939, the first-ever comic book devoted to just one character, according to History. DC's other big hero, Batman, reportedly first appeared months later in Detective Comics #27. The two made their first joint appearance in 1945 in a radio serial and first appeared in the same comic book in 1952.

Superman was censored by the United States government: During World War II, references to atomic bombs were censored, including an issue that featured Superman filming an atom bomb test for the Army, according to History.